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Biomedical subjects

M M Brown

Publications and source records attributed to M M Brown.

198 records · Page 11Linked to original sources
PubMedDate not supplied

Discrimination of metabolite from lipid and macromolecule resonances in cerebral infarction in humans using short echo proton spectroscopy.

Short-echo proton spectroscopy allows the noninvasive study of metabolites, lipids, and macromolecules in stroke patients, but spectra are difficult to interpret and quantify because narrow metabolite peaks are added to a broad background of lipid and macromolecule peaks. "Metabolite nulling" was used to distinguish the lactate peak from underlying lipid and macromolecule peaks. Increases in the lipid and macromolecule peaks were initially observed within the region of infarction in all patients, and further increases in lipid peaks were seen in five of the six patients during the following 6 weeks. The initial high lactate concentration decreases during the first 2 weeks after stroke, whereas lipid and macromolecule signals show a persistent elevation during the same period. Differences in the time courses of the observed changes suggest that lipid, macromolecule, and lactate signals arise from more than one source.

Adult↗
PubMedDate not supplied

Exudative retinopathy of adults: a late sequela of retinopathy of prematurity.

The cases of 11 patients with a unilateral, retinal detachment associated with hard exudate and other late sequelae of retinopathy of prematurity are described. The abnormality was first noted in the second to fourth decades of life. Ten of the patients were women and one was a man. The source of the hard exudate was thought to be telangiectatic retinal vascular abnormalities. Among the ten treated eyes, four demonstrated an improvement in visual acuity. In two cases a mass lesion was also noted in the fundus.

Adult↗
PubMedDate not supplied

Effects of haloperidol or SCH-23390 on ethanol-induced conditioned taste aversion.

Dopaminergic systems are thought to play an important role in the motivational effects of ethanol. The present experiments examined the effects of haloperidol (a D2 antagonist) and SCH-23390 (a D1 antagonist) on the acquisition of ethanol-induced conditioned taste aversion. In four separate experiments, adult male Swiss-Webster mice were acclimated to a 2-h/day water restriction regimen. Subsequently they received four conditioning trials consisting of 1-h access to either 0.2 M NaCl (experiments 1-3) or 0.15 % w/v saccharin (experiment 4). After flavor access on trials 1-3, subjects received either haloperidol (0.1, 0.15, or 0.3 mg/kg), SCH-23390 (0.05 mg/kg), or saline followed 30 min later by 0, 2, or 4 g/kg ethanol. Ethanol-flavor pairings reduced subsequent flavor intakes, indicating the development of conditioned taste aversion. Neither haloperidol of SCH-23390 reduced flavor intakes in the absence of ethanol. However, both haloperidol and SCH-23390 reduced ethanol-conditioned aversion depending on ethanol dose and conditioned flavor. These results are consistent with the notion that dopaminergic processes are important for the development of ethanol-induced conditioned taste aversion, and the notion that dopaminergic receptor systems influence both positive and negative motivational effects of ethanol.

Animals↗
PubMedDate not supplied

Quality of life associated with diabetes mellitus in an adult population.

To ascertain the quality of life associated with the health state of diabetes mellitus using utility value analysis. Consecutive adult patients with diabetes mellitus for at least 1 year and a mean age of 61.7 years (range 21-85 years) were interviewed in a cross-sectional fashion using standardized research methodology. Utility analysis values were obtained employing the time tradeoff method and were correlated with clinical parameters of the sample group, as well as with co-morbidities using the heteroscedastic Student's t-test and multivariate linear regression. The chi(2) distribution to test for independence was used to compare sample subgroups. With a sample of 292 patients, the mean, patient-preference-based, time tradeoff utility value associated with the health state of diabetes mellitus was 0.88 (standard deviation (SD)=0.17; 95% confidence interval (CI), 0.86-0.90). Repeat analysis confirmed the reproducibility of the data. Thus, the average diabetic was willing to trade away 12% of his or her remaining life in return for a diabetic-free health state. Factors associated with a significant decrease in diabetic-associated quality of life included: (1) the requirement for insulin (p=0.05), (2) the presence of depression (p=0.01), (3) the presence of diabetic retinopathy (p=0.03) and the presence of co-morbidities in general (p=0.01). The health state of diabetes mellitus has a significant effect upon patient, preference-based quality of life. The presence of diabetic co-morbidities and dependence upon insulin appear to decrease quality of life. The utility value associated with the health state of diabetes mellitus is of substantial importance for use in the calculation of cost-effective analyses.

Adult↗
PubMedDate not supplied

Cotton-wool spots.

A series of 24 consecutive patients presenting with a fundus picture characterized by a predominance of cotton-wool spots, or a single cotton-wool spot, is reported. Excluded were patients with known diabetes mellitus. Etiologic conditions found included previously undiagnosed diabetes mellitus in five patients, systemic hypertension in five patients, cardiac valvular disease in two patients, radiation retinopathy in two patients, and severe carotid artery obstruction in two patients. Dermatomyositis, systemic lupus erythematosus, polyarteritis nodosa, leukemia, AIDS, Purtscher's retinopathy, metastatic carcinoma, intravenous drug abuse, partial central retinal artery obstruction, and giant cell arteritis were each found in one patient. In only one patient did a systemic workup fail to reveal an underlying cause. The presence of even one cotton-wool spot in an otherwise normal fundus necessitates an investigation to ascertain systemic etiologic factors.

Adult↗
PubMedDate not supplied

The quality of life of patients with hypertension.

The authors evaluated the self-reported quality of life in patients with systemic arterial hypertension and assessed whether clinicians and normotensive respondents from the general public appreciate the impact that hypertension has on health-related quality of life. A quality-of-life questionnaire was completed by 385 individuals: persons with hypertension (n=188), normotensive persons (n=148), and clinicians (n=49). A utility score, which represents one's self-perceived health-related quality of life, was generated for each group by using standardized time tradeoff questionnaires. Quality of life with hypertension was judged to be significantly higher according to affected individuals (mean utility score, 0.980), compared with normotensive persons (mean utility score, 0.948) and clinicians (mean utility score, 0.942), who were asked to assume that they had hypertension (p<0.0005). Clinicians and normotensive individuals tend to overemphasize the impact that hypertension has on quality of life, as compared to affected patients. The relatively low impact that hypertensive individuals indicate high blood pressure has on their quality of life may contribute to their lack of compliance with treatment regimens.

Adaptation, Psychological↗
PubMedDate not supplied

Impact of carotid endarterectomy upon cognitive functioning. A systematic review of the literature.

BACKGROUND AND PURPOSE: The extent to which carotid endarterectomy (CEA) influences cognitive functioning has been the subject of a number of studies often with conflicting conclusions. This paper systematically reviews the literature in an attempt to clarify this issue. RESULTS: Although the majority of studies (16/28) reported an improvement in cognition after surgery, a substantial minority (12/28) found no change. Studies before 1984 tended to report an improvement, while later studies tended to report no change in cognition. Cognitive improvement was also more likely the longer the time interval between CEA and assessment. The studies were found to differ on many methodological factors, e.g. sample size, type of patient and control group, severity and side of carotid stenosis, the range of cognitive tests and timing of postoperative assessment. CONCLUSION: Given the conflicting findings, and the methodological issues, it is not possible to draw a clear conclusion regarding the impact of carotid endarterectomy upon cognition. Future research which pays attention to these methodological factors is needed in order to adequately resolve the current debate.

Carotid Arteries↗
PubMedDate not supplied

A single consultation cerebrovascular disease clinic is cost effective in the management of transient ischaemic attack and minor stroke.

AIM: We examined the cost effectiveness of a single consultation strategy to manage patients referred with TIA or stroke to our cerebrovascular disease (CVD) clinic, where all relevant investigations (blood tests, CT brain scan and carotid Dopplers) were obtained prior to the clinic appointment. DESIGN: Retrospective study of patients referred to the CVD clinic at St George's Hospital, London between October 1995 and 1996. RESULTS: Of 211 new patients seen in the clinic, 73% had CVD; 146 (68%) patients had imaging studies prior to clinic attendance. Of these, 132 (90%) were managed with a single consultation. This strategy cost 5,700 Pounds less than if these patients had been followed up. CONCLUSION: Performing all relevant investigations prior to clinic attendance allowed a fully informed discussion with the patient at a single consultation and was cost effective.

Aged↗
PubMedDate not supplied

Drug-drug interactions among residents in homes for the elderly: a pilot study.

This pilot study investigated epidemiologically the potential for clinically significant drug-drug interactions, a subclass of adverse drug responses, in two homes for the elderly. The agent (drugs), host (residents), and environment (rural and urban nursing homes) in the illness known as drug-drug interaction were studied. Drug profiles on 188 subjects were compiled and screened by computer. Of these, 100 (80 in the rural home and 20 in the urban home) had the potential for clinically significant drug-drug interactions. Laboratory diagnostic procedures essential to confirm the unintentional interaction of two or more drugs were beyond the scope of the study; therefore, physicians independently reviewed the records of 66 residents who could be interviewed, agreeing that 27 residents were potential drug-drug interactors. These subjects had twice as many drug products and three times as many pro re nata products prescribed for them as did subjects without the potential for drug-drug interaction. The possible cause of interaction found most frequently was digitalis combined with thiazide or furosemide. The results of this pilot study suggest several implications for practice within the research setting.

Aged↗
PubMedDate not supplied

Perceived stress and coping strategies among families of cardiac transplant candidates during the organ waiting period.

OBJECTIVE: To explore and describe perceived stress and coping strategies among families of candidates for cardiac transplant during the organ waiting period. DESIGN: This descriptive, multiinstitutional study was guided by the T-Double ABCX Model of Family Adjustment and Adaptation (McCubbin & Thompson, 1987). SETTING: Five tertiary care centers with transplant programs in three Southeastern cities. SUBJECTS: Thirty-eight family members of patients on the active list for cardiac transplantation, including 35 women and three men with a mean age of 44 years (SD = 13.17). Subjects had a family member on the waiting list for a mean of 6.5 months. INSTRUMENTS: Family members completed the following three instruments: (1) Family Inventory of Life Events and Changes (FILE), (2) Family Crisis Oriented Personal Scale (FCOPES), and (3) Family Perception of the Transplant Experience Scale (FPTES). RESULTS: Stress: 53% and 47% of respondents indicated that they were experiencing moderate and low degrees of stress, respectively. Coping: Family members used more coping mechanisms than normative subjects in the literature. Coping strategies used in order of decreasing frequency: (1) knowing our family has the strength to solve our problems, (2) facing problems head-on, and (3) seeking support from friends. Appraisal: Mean score of 32.13 reflects subjects' positive perception of the pretransplant experience. The three statements with which the subjects most strongly agreed: (1) heart illness has changed roles of family members, (2) family member will survive the transplant operation; and (3) this is an experience that could bring out the family's strengths. CONCLUSIONS: An increase in the number of coping strategies used with low to moderate stress levels suggests the effectiveness of coping strategies in mediating stress. The preference for active rather than passive coping strategies may be reflective of the selection criteria for transplant candidates or nursing interventions during this period to minimize stress and promote family coping.

Adaptation, Psychological↗
PubMedDate not supplied

Rheumatoid nodulosis. Sporadic and familial diseases.

Two patients are described with longstanding, multiple, subcutaneous nodules with the histopathological features of rheumatoid nodules. Neither patient had any clinical evidence of rheumatic disease. One patient had a family history of smiliar nodules transmitted as an autosomal dominant trait. Leukocyte function studies failed to reveal any defect to account for the nodule formation.

Female↗
PubMedDate not supplied

Repair of retinal detachment associated with congenital excavated defects of the optic disc.

Excavated defects of the optic disc have been associated with retinal detachment in the macula and beyond. Included among these defects are congenital pits of the optic disc, optic nerve colobomas, and the morning glory syndrome. We report eight consecutive patients with congenital, excavated defects of the optic disc and associated retinal detachment managed with pars plana vitrectomy, laser photocoagulation, and intravitreal gas injection.

Adolescent↗
PubMedDate not supplied

Structure-activity relationships of analogs of the endogenous brain peptides Tyr-MIF-1 and Tyr-W-MIF-1.

Analogs of the naturally occurring peptides Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2) and Tyr-W-MIF-1 (Tyr-Pro-Trp-GLy-NH2) were synthesized and investigated for their opiate agonist as well as antagonist activity in the guinea pig ileum assay. [Tyr5]-Tyr-MIF-1 and the endogenous Tyr-W-MIF-1 were the most potent opiate agonists among the 20 compounds tested. Several analogs showed antiopiate activity in the ileum from morphine-tolerant animals as measured by attenuation of the agonistic effect of DAMGO, which inhibits electrically stimulated contractions of the ileum. The binding activity of the analogs at mu opiate receptors was determined by displacement of [3H]-DAMGO in rat brain. Tyr-W-MIF-1 and its analogs were more potent than Tyr-MIF-1 and its analogs in this binding assay. Thus, Tyr-MIF-1, Tyr-W-MIF-1 and several of their analogs could act as opiate agonists as well as antagonists.

Amino Acid Sequence↗